1. Field of the Invention
The present invention relates to wedge and clamp locking systems. More particularly it relates to an improved wedge and clamp locking system for an excavator bucket tooth which employs a Whistler base for supporting the tooth on the mining lip of the excavator bucket along with a C-clamp for securing the Whistler base to the bucket lip. The clamp is held in place by a wedge driven between a portion of the bucket lip and the clamp.
2. Description of the Prior Art
The prior art relating to the present invention is shown in FIGS. 1 and 3 of the drawings. Thereshown is a portion of a mounting projection 13 for a digging tooth disposed on the mining lip 15 of a typical excavator bucket. A female locator receptacle 17 is disposed in the mounting projection 13. The receptacle is an opening for receiving a wedge and clamp. A Whistler base 19 is arranged on the mounting projection and a pair of seating surfaces 21 are disposed at the front end of an opening in the Whistler base which colocates with the locator receptacle in the mining lip. The seating surfaces align with the front end of the female locator receptacle, the front end being toward the lip of the mining bucket.
An excavator digging tooth 20 is secured to the Whistler base 19 with a pin 22 and the Whistler base is secured to the mining lip by means of a wedge 23 and clamp 25. The clamp 25 is inserted through the female locator receptacle 17 in the mining lip and the opening 27 in the Whistler base and wedged onto the seating surfaces 21 formed on the Whistler base. The seating surfaces lock onto the mounting projection 13 of the mining lip 15 due to the compression by the clamp of the seating surfaces 21 of the Whistler base onto the lip. A wedge 23 is driven between the back portion 29 of the clamp, which locks the Whistler base to the mining lip, and a portion of the mining lip 13 inside the female locator receptacle 17 to lock the Whistler base onto the mining lip.
The problem with the prior art is that during a working day of digging with the mining bucket, the wedges holding the digging teeth on the mining lip work loose and the operator of the excavator or an assistant must climb down and hammer the wedges 23 back into place to retighten the clamps 25.
In an effort to overcome the problem of the Whistler bases loosening up during digging, some attempts have been made to provide an interlock between the wedge and the C-clamp. However, in each of these cases the interlock is permanent and must be burned away by torches to disengage the wedge from the clamp. This is a time consuming and expensive solution which has seen considerable use, but it has proved very unsatisfactory.
There has therefore been a need in the industry to provide a dependable secure locking system for holding the Whistler base on the mining lip of excavator buckets: one which will not loosen up and yet can be easily unlocked. It will be seen from the disclosure of the present invention that the desired improvement and solution to the described problem has been achieved by the present invention.